1. Field of the Invention
The invention relates to a combined display and viewing system. Such system is able to simultaneously recognize background and display information without considerably changing a line of sight.
When using a video camera, it is desirable to have an indication of the elapsed recording time, the remaining capacity of a battery and the like, when viewing the scene to be filmed.
Further, in a case where a measuring operation using measuring instruments such as an oscilloscope, a tester and the like is carried out, it is desirable to look at both the measuring results, such as waveforms, and the measuring site simultaneously.
The elapsed shooting time, the remaining capacity of the battery and the like, or, the measuring results (hereinafter referred to as "display information") can be displayed by an LCD or the like.
For example, a video camera may be provided with a videotape drive section for performing driving of a video tape, a camera section for photographing a subject (background) and a finder section for displaying information such as elapsed shooting time, remaining capacity of a battery camera parameters when photographing.
In recent years, these sections have become small-sized and lightweight, and a video camera wherein these sections are integrated has been widespread.
When such video camera is used, a body of the video camera which contains the various sections is arranged in the vicinity of the face of the user. The camera section is directed to the subject, and the user's line of sight is directed to a finder section such that the user can see the subject or scene and the display information.
The display information together with the scene caught by the camera section is viewed via the finder section when the user directs his line of sight to the finder.
When a measuring instrument is used, it was up to now necessary that the user's line of sight is moved from a measuring position to display means for determining the measuring results. This is because it is in practice difficult to arrange the display means (body of the measuring instrument) at a location adjacent to the measuring position. In case where the measuring position is changed frequently, movement of the line of sight is frequently repeated.
For a smooth operation, it is necessary to have an arrangement which enables the user to view simultaneously the measuring site and the displayed measuring results.
In the case a video camera with a zoom lens set in the telephoto position to shoot an object which is fast moving, the subject may easily escape from the finder section. It is difficult then to catch again the object because of the limited field of view in the telephoto position. Then it becomes necessary to set the zoom lens in the wide-angle position, and to retract the eyes from the finder section in order to view the object directly, by visual observation and to determine the direction of a line of sight towards the object. For such operation, the user has to use his/her hands and hand-free operation is not possible. When the camera body needs to be held close to the user's eye for a long period of time, the user's hands become fatigued.
2. Description of the Related Art
Video camera's with a finder section separated from the video camera body so that the camera body need not to be located adjacent to the face of the user are known from a.o.
Japanese Patent Laid-open No. HEI 1-276973 (reference (1)),
Japanese Patent Laid-open No. HEI 2-121576 (reference (2)),
Japanese Patent Laid-open No. HEI 2-250567 (reference (3)), and
U.S. Pat. No. 4,672,436 (reference (4)). These references disclose arrangements wherein the finder section (View-finder) is provided on an auxiliary element. The auxiliary element is of spectacle type or substantially of headgear type and is to be mounted on a user's head. When the auxiliary element is mounted on the head, the finder section is arranged before the eyes of the user.
In the arrangements of references (1) to (4), the body of the video camera needs no longer to be arranged adjacent to the user's face, to look into the finder. However, the body on which a camera section is provided is hand-held, and the optical axis of the camera should be changed in agreement with the motion of the subject, so that movement of the body is still required. When a fast moving subject is escaped, the operation to catch the subject again will be difficult.
In the field of measuring instruments, arrangements have been realized in which measuring results are made audible so that operation can be continued without movement of the line of sight from a measuring site. However, it takes time to generate the audible signal, so that rapid or fast operation cannot be realized. A further problem arises when the measuring instrument does not provide waveform data or simple numerical data or the like.